The public hearings will be held on January 29, 2015, in Washington, DC and Arlington, Texas, and on February 2, 2015, in Sacramento, California. Please refer to SUPPLEMENTARY INFORMATION for additional information on the public hearings.

40 CFR Parts 50, 51, 52, 53, and 58

Summary

The Environmental Protection Agency (EPA) is announcing three public hearings for the proposed rule titled, “National Ambient Air Quality Standards for Ozone,” that was published in the Federal Register on December 17, 2014. The hearings will be held in Washington, DC, Arlington, Texas, and Sacramento, California. Based on its review of the air quality criteria for ozone (O 3 ) and related photochemical oxidants and national ambient air quality standards (NAAQS) for O 3, the EPA proposes to make revisions to the primary and secondary NAAQS for O 3 to provide requisite protection of public health and welfare, respectively. The EPA is proposing to revise the primary standard to a level within the range of 0.065 to 0.070 parts per million (ppm), and to revise the secondary standard to within the range of 0.065 to 0.070 ppm, which air quality analyses indicate would provide air quality, in terms of 3-year average W126 index values, at or below a range of 13-17 ppm-hours. The EPA proposes to make corresponding revisions in data handling conventions for O 3 and conforming changes to the Air Quality Index; to revise regulations for the Prevention of Significant Deterioration program to add a transition provision for certain applications; and to propose schedules and convey information related to implementing any revised standards. The EPA is proposing changes to the O 3 monitoring seasons, the Federal Reference Method (FRM) for monitoring O 3 in the ambient air, Federal Equivalent Method procedures for testing, and the Photochemical Assessment Monitoring Stations network. Along with proposing exceptional event schedules related to implementing any revised O 3 standards, the EPA is proposing to apply this same schedule approach to other future revised NAAQS and to remove obsolete regulatory language for expired exceptional event deadlines. The EPA is proposing to make minor changes to the procedures and time periods for evaluating potential FRMs and equivalent methods (including making the requirements for nitrogen dioxide consistent with the requirements for O 3 ) and to remove an obsolete requirement for the annual submission of documentation by manufacturers of certain particulate matter monitors.

Written comments on this proposed rule must be received by March 17, 2015. Public Hearings: The EPA intends to hold three public hearings on this proposed rule in January 2015. These will be announced in a separate Federal Register notice that provides details, including specific dates, times, addresses, and contact information for these hearings.

40 CFR Parts 50, 51, 52, 53, and 58

Summary

Based on its review of the air quality criteria for ozone (O 3 ) and related photochemical oxidants and national ambient air quality standards (NAAQS) for O 3, the Environmental Protection Agency (EPA) proposes to make revisions to the primary and secondary NAAQS for O 3 to provide requisite protection of public health and welfare, respectively. The EPA is proposing to revise the primary standard to a level within the range of 0.065 to 0.070 parts per million (ppm), and to revise the secondary standard to within the range of 0.065 to 0.070 ppm, which air quality analyses indicate would provide air quality, in terms of 3-year average W126 index values, at or below a range of 13-17 ppm-hours. The EPA proposes to make corresponding revisions in data handling conventions for O 3 and conforming changes to the Air Quality Index (AQI); to revise regulations for the prevention of significant deterioration (PSD) program to add a transition provision for certain applications; and to propose schedules and convey information related to implementing any revised standards. The EPA is proposing changes to the O 3 monitoring seasons, the Federal Reference Method (FRM) for monitoring O 3 in the ambient air, Federal Equivalent Method (FEM) procedures for testing, and the Photochemical Assessment Monitoring Stations (PAMS) network. Along with proposing exceptional event schedules related to implementing any revised O 3 standards, the EPA is proposing to apply this same schedule approach to other future revised NAAQS and to remove obsolete regulatory language for expired exceptional event deadlines. The EPA is proposing to make minor changes to the procedures and time periods for evaluating potential FRMs and equivalent methods (including making the requirements for nitrogen dioxide consistent with the requirements for O 3 ) and to remove an obsolete requirement for the annual submission of documentation by manufacturers of certain particulate matter monitors. For additional information, see the Executive Summary, section I.A.